Mechanism and method for connecting ends of metal tubing

ABSTRACT

A mechanism and method for connecting ends of coiled tubing for insertion and use in a well bore of a gas or oil well. The mechanism and method requires only a sleeve for insertion into the ends of the coiled tubing to be connected and a roll forming operation to produce mating circumferential grooves in the sleeve and coiled tubing surface to achieve the desired connection.

BACKGROUND OF THE INVENTION

The present invention relates to a mechanism and method for connecting the ends of coiled tubing for insertion into a well bore.

In oil drilling and other well operations, coiled tubing is used for raising and lowering tools into the well bore. This is achieved by attaching a tool to the end of a reel of coiled tubing. By reeling out the coiled tubing, the tool may be lowered to the desired location within the well. Various tools for gathering data and the like may be attached for placement within the well bore. In instances in this application where additional coiled tubing lengths are required, it is necessary to connect the ends of two lengths of coiled tubing.

Prior art practices used for connection of coiled tubing ends require the use of a separate connector that is cumbersome and expensive both from the standpoint of manufacture and use.

The present invention provides a connector mechanism and method for connecting ends of coiled tubing without requiring a separate connector. In addition, the mechanism and method of the invention may be easily applied in the field.

SUMMARY OF THE INVENTION

The invention relates to a mechanism for connecting ends of metal tubing, such as coiled tubing for insertion and use in a well bore of a gas or oil well. The mechanism includes a metal sleeve having an outside diameter of a size for insertion into opposed ends of metal tubing to be connected. This sleeve has a plurality of circumferential grooves on an outside surface thereof, each in mating connection with circumferential grooves on an outside surface of the metal tubing at the opposed ends thereof to connect the tubing at these opposed ends.

The sleeve may have a plurality of additional circumferential grooves on an outside surface thereof with each of the plurality of additional circumferential grooves having an O-ring seal therein for sealing the ends of the metal tubing against fluid leakage from the metal tubing at the opposed ends thereof.

In accordance with the method of the invention, a metal sleeve is provided having an outside diameter of a size for insertion into opposed ends of metal tubing to be connected. A plurality of circumferential grooves are formed on an outside surface of the sleeve. The sleeve is inserted into the opposed ends of the metal tubing to be connected with the opposed ends being in an abutting engagement. A plurality of circumferential grooves are formed on an outside surface of the metal tubing at the opposed ends thereof and in mating connection with the circumferential grooves on the outside surface of the sleeve.

Further in accordance with the method of the invention, a plurality of additional circumferential grooves may be formed on an outside surface of the sleeve and in each an O-ring seal is mounted for sealing the ends of the metal tubing against fluid leakage from the metal tubing at the opposed ends thereof.

The grooves may be formed by the use of a roller.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one several embodiments of the invention and together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view in partial vertical cross-section of end sections of two metal tubing to be connected;

FIG. 2 is a view in partial vertical cross-section of a sleeve for insertion into the ends of the metal tubing and two forming rolls for producing two circumferential grooves therein;

FIG. 3 is a vertical cross-section of the sleeve of FIG. 2 showing two rollers forming two circumferential grooves in the sleeve of FIG. 2;

FIG. 4 is an assembly view in partial cross-section of the sleeve and the coiled tubing ends; and

FIG. 5 is an assembly view showing the assembly of FIG. 4 with forming rolls having provided circumferential grooves in the surface of the coiled tubing ends and in mating engagement with the circumferential grooves in the sleeve shown in FIG. 3.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

With reference to the drawings, and presently to FIG. 1 thereof, there is shown two end portions of coiled tubing 1 and 2 for connection.

With reference to FIG. 2, there is shown a sleeve 3 having circumferential grooves 4 and 5 produced by rollers 6.

In FIG. 3, sleeve 3 is shown having additional circumferential grooves 6 and 7 produced by rollers 8.

In FIG. 4, the coiled tubing sections 1 and 2 of FIG. 1 are shown in abutting engagement and in assembly with sleeve 3. O-ring seals 9 and 10 are mounted in grooves 4 and 5 to seal the assembly against fluid leakage at the abutting ends of the coiled tubing sections 1 and 2.

FIG. 5 shows the assembly of FIG. 4 with circumferential grooves 11 and 12 formed by rollers 13 in engagement with circumferential grooves 6 and 7 of the sleeve 3 to connect the coiled tubing ends in locking engagement for reeling into a well bore. 

1. (canceled)
 2. (canceled)
 3. A method for connecting ends of metal coiled tubing for insertion and use in a well bore of a gas or oil well, comprising: providing a metal sleeve having an outside diameter of a size for insertion into opposed ends of said coiled tubing to be connected; roll forming a plurality of circumferential grooves on an outside surface of said sleeve; inserting said sleeve into said opposed ends of said coiled tubing to be connected with said opposed ends being in abutting engagement; roll forming a plurality of circumferential grooves on an outside surface of said coiled tubing at said opposed ends thereof and in mating connection with said circumferential grooves on said outside surface of said sleeve.
 4. The method of claim 3, wherein a plurality of additional circumferential grooves are provided by roll forming on an outside surface of said sleeve and in each said plurality of additional circumferential grooves an O-ring seal is mounted therein for sealing said ends of said metal tubing against fluid leakage from said metal tubing at said opposed ends thereof.
 5. (canceled) 